The present invention relates to a clamping device for attaching a tool holder to various kinds of machine tools including a lathe, a numerical controlled lathe and an automatic copying lathe.
A conventional tool assembly 101 comprising a support body 102 and a plurality of tool holders 111 is depicted in FIG. 8. A clamping device for each tool holder 111 shown in FIG. 8 is provided with a wedge-type holder clamping tool 112 having a plurality of fastening bolts 114 and one jack-up bolt 113. A plurality of fastening bolts of the wedge-type holder clamping tool are fastened to the support body 102, so that the tool holder can be connected to the support body via interaction between respective wedge surfaces (not shown) of the wedge-type holder clamping tool 112 and the support body, which interaction pushes the clamping tool 112 against the tool holder 111. When the tool holder is to be removed from the clamping device, the jack-up bolt 113 that has been loosened in advance is screwed against the support body after the plural clamping bolts are loosened, so that the wedge surface of the wedge-type holder clamping tool is forcefully moved away from the wedge surface of the support body. Thus, the tool holder can be removed.
Various kinds of devices for simplifying attachment/removal of the tool holder are well known. A device for holding a tool holder shank in a machine tool is disclosed in Japanese Unexamined Patent Publication No. 2000-190110. The device releasably holds a holder shank of the tool holder to which a cutting insert is attached and a lock rod is provided on a base member. The attachment/removal structure between the holder shank and the lock rod is complicated and it is difficult to reduce the size of the device.
Japanese Unexamined Patent Publication No. 2001-300802 discloses a detachable securing mechanism of a cutting tool used in a comb-type tool rest of a machine tool such as a numerical controlled lathe. The mechanism is provided with a supporting member for supporting an arrangement of plural tools. The supporting member attaches the cutting tool to the comb-type tool rest of the machine tool by fastening a plurality of mounting bolts.
However, in the above conventional clamping device for a tool holder, it takes a long time to attach/remove the tool holder because it is required that a plurality of clamping bolts are fastened or loosened in attachment/removal of the tool holder.
Accordingly, there is a problem in miniaturization and simplification of the device because the structure of the device is complicated. In addition, it is difficult to repeatedly and accurately set the position of a top cutting edge because the placement of the cutting holder at a predetermined position must be visually checked.
In view of the above conventional prior art, the object of the present invention is to provide a clamping tool capable of reducing an attachment/removal time when one or plural tool holders, especially small tool holders, are attached to or removed from the machine tool such as the lathe, the numerical controlled lathe and the automatic copying lathe, and capable of improving the accuracy in positioning of the tool holder.